Refactoring and API change

All logic has been rewritten in python co-routines and should bring a significant performance boost.

Old syntax (experiment.Base) is now deprecated and new experiments should use the better syntax with @reg_exp(...). In case you have old experiments you can use --compatibility-mode. I tested all major functionality using old example code and it should work. In case not, fallback to v1.0.0 and open an issue.